A hard lesson about Sandisk SD cards

[corster]

I put keywords in the Topic Description so that anyone doing research can find this post a little easier and, thus, avoid themselves the headaches of the sandisk SD cards. I am a newbie zaurus user and I love my zaurus. I've only had it for about a week and I've had to hard reset it a few times because of this stupid SANDISK SD card. I figured that any card would do, went out, and bought the sandisk because of the price. (sadly I was offered a different brand at twice the space for only $10 more). Well a couple of days into having installed the sd card and it corrupted all of the data that I put on it. Sometimes it wouldnt even allow me to eject it and when I attempted to power it down the zaurus just locked. I mean Locked-Locked. Software reset wouldn't work so into the battery compartment I went to press the little button. Luckily for me, I was able to fish the receipt and packaging out of the trash and am on my way out the door to exchange this piece of crap for a better one. My biggest mistake was that I didn't research first. Save yourself the trouble.. .don't buy sandisk and always do research in this wonderful forum first before buying something.

I've learned my lesson!

-cor-

[jerrybme]

While you are correct that many have reported problems with the Sandisk and you're probably better off with a different brand. I suspect the real problem is the SD drivers and that Sandisk doesn't play well with them. Unfortunately, they are not open source so no one's been able to improve them.  I wonder if Sharp improved the SD drivers, would the problems go away?

I've been using a 512 mg Sandisk card for over a year. I did have problems with it once after putting a swap partition on it. (given how slow the SD interface is, I don't know what I thought I was doing  )  It was ext2 formatted and I couldn't get my Z to reformat it or read the contents. I put it in a card reader and formatted it ext2 again with my pc, no problem and it's worked fine since. This only worked using a linux PC, Winbloze couldn't format it back to FAT (I tried that first).  

Bottom line, never trust ANY storage media, ALWAYS backup and if you do have a SD card that gets corrupted try reformatting it with a linux PC & card reader before you give up on it.

Cheers,
Jerry

[TheHeretic]

I did have problems with it once after putting a swap partition on it. (given how slow the SD interface is, I don't know what I thought I was doing  )  It was ext2 formatted..

Is there a major difference between SD and MMC? I've been using ext2 formatted MMC cards with swapfiles on two Z's now for well over 18 months with no problems, doesn't seem that slow either.

The general consensus regarding Sandisk cards though does seem to be - avoid them!!!

[misterpib]

Apparently speed is the main difference, and the ability to "lock" the card (the Zaurus doesn't support security features of the SD cards does it?)

Anyhow, I found a site that did some timing tests with the two cards:
Speed of SD vs. MMC

But yeah, in general, the SD cards are supposed to be 4 times faster than the MMC cards.

[jerrybme]

Another good site : http://www.flashcards.co.nz/knowlege-base/...vs-sd-card.html

Interestingly, SanDisk help develop the encryption technology of the SD and their cards are the one that seem to not work well with Sharp's SD drivers. Hmmm, wonder if there's any corelation  

Cheers,
Jerry

[TheHeretic]

Apparently speed is the main difference, and the ability to "lock" the card (the Zaurus doesn't support security features of the SD cards does it?)

Anyhow, I found a site that did some timing tests with the two cards:
Speed of SD vs. MMC

But yeah, in general, the SD cards are supposed to be 4 times faster than the MMC cards.

LOL!
Yes, I mean't beyond that   I understood that the Z uses SD cards without security support so a card behaves like a MMC card.  That's why I've never bothered with SD. Interesting point about SD being x4 faster than MMC, I'll have to look into it some more, but I've been happy with the MMC cards I've had so far from Jessops.

[dougeeebear]

Here'a a link to an updated SD card driver for the SL-5500 that might possibly help you with your SD problem. I increased the write speed on mine by about 250%.
There was a slight read speed improvement. My SD card is a SimpleTech 128mb.
I have installed a lot of programs to it instead of internal memory, plus I use it for my backups. Works out very well for me.

http://www.zaurususergroup.com/modules.php...download&sid=52

[corster]

I'll go ahead and give the new driver a try. I have 30 days to return the card anyway so if it craps out within that time, I still have the option of returning it. In the meantime, I have not installed anything important on the SD card and have backed up my current config.... It was kind of a pain at first to have had to setup all the apps and services all over again, but I have it all down to a science now.... I know you're all thinking "why not backup beforehand?" well.. I had... the backup was on the originally corrupted SD card  But, I found a compactflash card that I have had for a while that I will use for backups from now on.  Thanks for the suggestions!

-cor-

[Omicron]

Here'a a link to an updated SD card driver for the SL-5500 that might possibly help you with your SD problem. I increased the write speed on mine by about 250%.
There was a slight read speed improvement. My SD card is a SimpleTech 128mb.
I have installed a lot of programs to it instead of internal memory, plus I use it for my backups. Works out very well for me.

http://www.zaurususergroup.com/modules.php...download&sid=52

Does the driver have any effect on the C860 SD speed?

[dougeeebear]

If you read the description, it says that it is a replacement for the SL-5500 driver. No other info is available there. But you never know, it might work on C860.

Also --very important-- I made a folder on a 256mb CF card called "SD Card Backup" where I periodically copy the contents of my SD card to. This is a good safety net.

[corster]

well, rather than reinstalling drivers I went ahead and formatted the SD card as ext. I figured I might as well give it a try before returning it anyway. So far everything seems to be working just fine and no garbage files have shown up yet after some rigorous testing (i.e. transferring large file while being wirelessly connected). I still have another 3 weeks to return the card if I have to, but after reading other peoples posts it looked like there was some hope for this card after all.

-cor-

[Guest]

According to a panasonic website I read about SD cards, you should not reformat them, unless you use their special SD reformatting tool. Reformatting them with other tools can destroy them (This happened to me - I have a SD card that can no longer be read or formatted in anything I've tried - Zaurus, Digital Camera, 3 different PC memory card readers).

[seekyrr]

I need to get a SD soon.  Looks like scan is out so would you guys recomend Lexar or Kingston or Dane-Elec?

Also, is there a hardware limit for the write speed in a Z 5500?  Lexar has a 32X write one but I wonder if I would really be able to take advantage of that with the hardware.

Thanks

Seek

[nacs]

I had this exact same problem with a SD card from Sandisk (corruption). I fortunately found the problem within literally 24 hours of purchasing and was able to return it to the store for a different brand (Panasonic--which has worked flawlessly).